Insecticidally and acaricidally active mono-and dithiophosphoric acid esters



United States Patent 3,022,215 INSECTICIDALLY AND ACARICIDALLY ACTIVE MONO- AND DITHIOPHOSPHORIC ACID ESTERS Max Schuler, Arlesheim, Switzerland, assignor to Sandoz A.G., Basel, Switzerland No Drawing. Filed Mar. 8, 1960, Ser. No. 13,424 Claims priority, application Switzerland Apr. 30, 1959 18 Claims. (Cl. 167-22) The present invention relates to insecticidally and acaricidally active monothiophosphoric acid esters and dithiophosphoric acid esters, and to compositions containing such esters. The invention extends also to the use of the said esters and compositions containing the same for comhating pests, especially insects and spider mites.

The monoand dithiophosphoric acid esters of the present invention are representable by the formula n10 Y 0 R;

\H g i ps-orn- N-oooR.

wherein each of R R R and R is a methyl (CH or ethyl (C H group, and Y is an oxygen (0) or sulfur (S) atom.

The compounds of Formula I can be prepared by reacting a compound of the formula wherein R and K, have the precedingly-indicated significances, and X is a halogen atom, with a compound of formula R20 (III) wherein R R and Y are as precedingly defined, and Z is a cation. Where Z is a hydrogen atonythe reaction is carried out in the presence of an acid-binding agent.

It is preferred that the reaction be efiected in a solvent, such as water, acetone, methylethylketone, dioxane or the like, or in aliphatic or aromatic hydrocarbons, or in a mixture of such solvents, at ambient or slightly elevated temperature.

Illustrative of suitable compounds of Formula II are e.g. chloroacetyl-N-alkyl-carbamic acid alkyl esters, such as chloroacetyl-N-niethyl-carbafic acid methyl ester and chloroacetyl-N-methyl-carbamic acid methyl ester as well as chloroacetyl-N-ethyl-carbamic methyl ester and chloroacetyl-N-ethyl-carbamic acid ethyl ester; also the corresponding bromoacetyl compounds. (See, in this connection, Swiss Patent No. 194,377.)

Illustrative of suitable compounds of Formula 131 are for example:

etc.

The compounds of Formula I, supra, prepared by the precedingly described process, are liquid at room temper? ature (about 20 to about 30" 0.). They are stable in aqueous suspension, and are generally soluble in oils and in organic solvents. The new esters are outstandingly suitable for combating pests, more especially insects and spider mites (Tetranychidae sp.) in the protection of plants.

The compounds of Formula I are distinguished, relative to the corresponding non-N-alkylated compounds of the formulae:

oin50 o H rs-cm-cnrncooohi;

by a surprisingly higher insecticidal and systemic activity.

* employed, and these were tested on the following insects:

cockroaches (Periplanata americana), grasshoppers (Carausius morosus) and flour worm (Tenebrio molitor). Of each of these types, larvae of the last stage were employed. The tests were carried out as follows:

10 specimens of each type were sprayed with the above several emulsions by means of a hand spray gun at a pressure of about 1 atmosphere until the insects as well as the bottoms of the containers were uniformly wetted. The test pests remained in the sprayed containers for three days, after which the surviving ones were transferred to clean containers.

The cockroaches and flour worms were fed during the test period with untreated wafers made of sugar and starch. The grasshoppers were fed with ivy which had been sprayed, together with the test insects, with the emulsion concerned.

The toxic action of the compounds was checked daily by counting the paralyzed and killed individuals. The observed results are characterized by the following characteristic values:

. (a) K-value.-I.e. the number of test individuals of the above-namedthree types, which were paralyzed or killed 24 hours afterthe treatment, expressed in percentof the initial number of test individuals.

(b) M-valire. I.e. the number of dead test individuals canto 3 of the above-named three days after the treatment, expressed in percent of the initial number of test individuals.

TABLE I Compound K-value M-value CHzO\fi H PS-CHa-C-NHCOOCnHs 3 6 CHsO The results clearly show that the radical R in the com,- pounds of Formula I is of decisive significance for insecticidal action.

In comparison with compounds which have no group connected to the nitrogen atom, the esters'of the present invention exhibit the advantage of essentially lower toxicity to warm-blooded animals, as shown by the following comparative results:

TABLE II Toxicity to Warm- -Blooded Animal DL-50, oral, white r mouse, mgJkg.

Compound CHsO In practicei.e. in the field or garden as well as 'in' the greenhouse or in the home,,etc.-+-the combating of pests with the aid of the monoand dithiophosphoric acid esters of Formula I is preferably carried out by adsuspensions contain 0.005 to 0.2% by weight of active ester I.

However, the monoand dithiophosphoric acid esters I can also be used without addition of emulsifiers, but can, if necessary or desired, be worked up into dusting or scattering compositions with an inert carrier, such as talc, kaolin, kieselguhr, bentonite, etc. or with a mixture of such carriers, if necessary or desired also with addition of an adhesive agent.

The following examples set forth presently-preferred exemplary embodiments of the invention, solely by way of illustration and not by way of limitation. In these examples, parts are by weight unless otherwise indicated; the relationship between parts by weight and parts by volume is the same as that between grams and milliliters. Percentages are by weight; temperatures are in degrees centigrade.

Example 1 monium 0,0-dimethyldithiophosphate are refluxed together with 350 parts by volume of acetone, for 2 hours and while stirring the mixture. After cooling the latter, 1000 parts by volume of water are added, the diluted mixture extracted with ether, and the ether extract dried with sodium sulfate. After distilling ofi the ether, there is obtained a bright yellow oil which consists chiefly of the compound of the formula at 6 r PS-CHr-G-N-G 0 0 0:115

n 1.5154. S calculated: 21.3%. Found: 21.9%. N calculated: 4.7%. Found: 4.7%.

- 1 A Example 2 The procedure according to Example 1 is repeated with 90 parts of chloroacetyl-N-methyl-carbamic acid ethylester and 102 parts of ammonium 0,0-diethy1dithiophosphate, as starting materials, thereby obtaining a practically colorless oil consisting of the compound of the. formula 0.11.0 s 0 on,

i s-oHP -r't-ooomrn (hHgO 72 1.5049. S calculated: 19.5%. Found: 20.0%. N calculated: 4.3%. Found: 4.4%.

' Example 3 42 parts of bromoacetyl-N-methyl-carbamic acid methylester (B.P. 115) and 41.6 parts of sodium 0,0-

diethyldithiophosphate are stirred together for 2 hours at -70 in 150 parts by volume of methylethylketone. After cooling the mixture, 500 parts by volume of water are added, the diluted mixture extracted with chloroform, and the chloroform extract dried with sodium sulmixing the ester with an emulsifier, e.g. witha liquid polyglycolether resulting from the addition of ethylene oxide onto a high'molecular alcohol, mercaptan or alkylphenol, emulsifying the resultant mixture in water, and: then spraying the obtained emulsion onto the surfaces to be treated. Further suitable organic solvents,'such'as monoorpoly-alcohols, ketones,'aromatic hydrocarbons,

mineral oils, etc., can be incorporated into the emulsionas .solution aids. However, solid carriers such as talc,

' kaolin, kieselguhr, bentonite, etc. can also be incorporated fate. After distilling oif the solvent, the compound of the formula is obtained as a yellow oil, r1 1.5218. N calculated: 4.4%. .Found 4.3%.

liquid or pulverulentproducts of theindicated type are;

converted into aqueous emulsions or dispersions prior to use, itbeing preferable that the resultant emulsions or Example 4 the course of minutes at 10-15 after which stirring is continued for '6 more hours at 60-70". After cooling the resultant mixture to 500 parts by volume of water are stirred in, the benzene layer separated in a separatory funnel, dried with sodium sulfate, and the solvent distilled off on the water bath, finally in a water jet vacuum. The product is identical with that according to Example 2, and is obtained as a light oil.

Example 5 wt it is shaken out with 500 parts by volume 'of water, the oily product which separates is taken up in ether, and the product worked as in Example 1, whereupon the compound of the formula is obtained as a light yellow oil, 11 1.4828. N calcu- 24 parts of pulvelulent potassium carbonate are added lated: 4.7% Found: 4.9%.

TABLE 111 Example No. Compound Properties Analyses, pelican S calc., N eale., found found s 1 s-orn-oN-o 0 o (1H3 light yellow oil, m 1.5292 g g;

CHKO

CHsO SI I C2115 9 Ps-orn--n-o o 0 on: light yellow oil, on 1.5194 3 i2 CHaO CzH5O\fi 3 2 5 10 PS'CH2CN'C 00 CH; light yellow oil, no 1.5118 021150 CzHaO S 02115 11 l SCH5CN-C 0 O 02H; practically colorless oil, no 1.5048... I fig C1H5O C2H O\fi 9 (EH;

l2 PSCHg-:NC 0 0 02H; light yellow oil, 1m 1.477s i2 CQmO to 150 parts by volume of acetone, after whichwhile stirring slowly56 parts of 0,0-diethyldithiophosphoric acid are added. After the addition of 50 parts by volume of water, 49.7 parts of chloroacetyl-N-methylcarbamic acid methylester (B.P. 103-405") are added dropwise, followed by stirring of the mixture for two more hours at 50-55 After working up the resultant reaction mixture after the manner described in Exampie 1, the product according to Example 3 is obtained as a practically colorless oil.

Example 6 83 parts of chloroacetyl-N-ethyl-carbamic acid ethylester (B.P. l18-l20) and 98 parts of potassium 0,0- dimethyldithiophosphate are stirred together in 350 parts by volume of dioxane for four hours at 60-70. After cooling the reaction mixture, 500 parts by volume of water are added thereto, the diluted mixture shaken out with ether, and the resultant ether solution separated. After distilling ofi the Solvent, the compound of the formula CHgO S O C2 5 oH3o is obtained as a practically colorless oil, n 1.5118. S

calculated: 20.3%. Found: 20.7%. N calculated: 4.4%. Found: 4.4%.

Example 13 50 parts by weight of the ester of the formula are admixed with 50 parts of isooctylphenylheptaglycol ether, 2. clear solution being obtained. An aqueous emulsion of this solution, which emulsion contains 0.02%

of the ester, is sprayed on young apple trees infested with aphids. In a short time, all the aphids are dead.

Example 14 20 parts of the ester of the formula 60 parts of xylene, the product being of good emulsi-' A 0.1% aqueous emulsion of such,

fiability in water. product is sprayed on aphid-infested potted plants (cinneraria, asters, chrysanthemums). All the aphids are killed in a short period of time. The compound of the indicated formula may, .with like success, be replaced by a corresponding quantity of the ester of the formula CzHsO S 02H; i s-onr-b-u e-ooocn,

CaHzO Example 16 An excellently water-emulsifiable agent is obtained by admixing parts of the ester of the formula PS-OHz-C-N-COOCH;

with 20 partsof diisohexyl/heptylphenylhexaglycolether and 60 parts of a mixture consisting of 3 parts of propyleneglycol and one part of butoxyethoxyethanol. An aqueous emulsion of this agent, which emulsion contains 0.02% of said ester, effects a complete kill of aphids-sprayed therewith-in a short time.

The said ester may be replaced by the corresponding quantity of the ester of the formula olHao s w 0 0H, H IJ I PSCH1 -N-CO 0 OH;

with like success.

Example 17 A product of good emulsifiability in water is obtained by admixing parts of the ester of the formula 011 0 S on,

\I! H l PS-CHrC-N-GOOCHa on o with 25 parts of diisohexyl/heptylphenylhexaglycolether, 25 parts of xylene and 25 parts of diethyleneglycol. Potted spiderwort (T radescantia virginica) plants of about 20 cm. height are Watered with 100 cc. of an emulsion of the said product, which emulsion'contains 0.02% of the active ester, without touching the green parts of the plants. One day later, carausius larvae in the second starge of development are placed on the thus-treated plants. The larvae-take in together with the leaf parts which they eat, also the active agentthe compound of the aforesaid formula-which is absorbed by the plant through its roots and transported into the leaves. After 8 days, all thelarvae were dead.

A 0.1% aqueous emulsion of the same active agent was sprayed onto' Canadian erigeron (Erigerpn canaa densis) plants, infested with aphids,,in such manner that only. the lower parts of the plants (not the roots) were i wetted, while the upper parts of the plants-awhich were In two or three If bean plants in the two-leaf stage, infested with Aphis fabae, are sprayed with an aqueous emulsion of the same product, which emulsion contains 0.02% of the said ester, the aphids are dead in several hours.

The ester employed in the present example can, with like success, be replaced by a corresponding quantity of the ester of the formula or of the formula Example 18 A pulverulent product of good suspendability in water is obtained if 15 parts by weight of the ester of the formula CHsO (32H;

are thoroughly admixed with 3 parts of tort. dodecylmercaptanundecaglycolether, 7 parts of powdered silica gel and 75 parts of kaolin. An aqueous suspension of this product, which suspension contains 0.05% of the said ester has a killing action in a short time when sprayed on aphids.

The ester employed in the present example can, with like success, be replaced by a corresponding quantity of the ester of the formula Example 19 2 parts of the ester of the formula s it PsoH,-1-NG0ooiH,

C2H5O v are admixed with 98 parts of talc and the mixture is 50 parts of the ester of the formula \II N I PsoH,-o-N-o 0 o 02H! are admixed with '40 parts of'tert. dodecylmercaptanundecaglycolether [C H S(CH CH O) H] and 10parts of a mineral oil with the following properties: boiling point 320-405 20-30% sulfonatable fractions, specific gravity (20) 0.90-0.92. A clarsolution of good wateremulsifiability is obtained. 7 An aqueous emulsion of this solution, which emulsion contains 0.02% of the said ester, has a total killing action on aphids in a few hours.

A like action is realized if, instead :of the said ester,

stages of development thereof. Similar results are obtainable by replacing the ester of Example 8 by the corresponding quantity of any one of the esters of Examples 1, 2, 3 and 9.

Having thus disclosed the invention what is claimed is:

1. The method of combating insecticidal and acaricidal pests which comprises bringing the said pests into contact with an elfective quantity of a compound of the formula wherein each of R R R and R is an alkyl group containing a maximum of two carbon atoms, and Y is a member selected from the group consisting of O and S.

2. The method of combating insecticidal and acaricidal pests which comprises bringing the said pests into contact with an effective quantity of a compound of the formula 5. The method of combating insecticidal and acaricidal pests which comprises bringing the said pests into contact with an efiective quantity of a compound of the formula 6. The method of combating insecticidal and acaricidal pests which comprises bringing the said pests into cont-act with an effective quantity of a compound of the formula OHaO S 7. The method of combating insecticidal and acaricidal 1o pests which comprises bringing the said pests into contact with an effective quantity of a compound of the formula CaHsO 0 CH 8. A water-emulsifiable insecticidal and acaricidal concentrate consisting essentially of a compound of the formula wherein each of R R R and R is an alkyl group containing a maximum of two carbon atoms, and Y is a member selected from the group consisting of O and S, and an emulsifier therefor.

9. A water-emulsifiable insecticidal and acaricidal concentrate consisting essentially of a compound of the formula Y i somi i-i rcoont R20 wherein each of R R R and R is an alkyl group containing a maximum of two carbon atoms, and Y is a member selected from the group consisting of O and 8,

an emulsifier therefor, and a solid carrier.

10. An insecticide-acaricide consisting essentially of an aqueous emulsion of a compound of the formula wherein each of R R R and R is an alkyl group containing a maximum of two carbon atoms, and Y is a member selected from the group consisting of O and S, said insecticide-acaricide containing 0.005 to 0.2% by weight of said compound.

12. A compound of the formula wherein each of R R R and R is an alkyl group containing a maximum of two carbon atoms, and Y is a member selected from the group consisting of O and S.

13. A compound of the formula omo s 0H,

%S-CH2- 1 ICO 0 02B! CH3O 14. A compound of the formula CgHsO S O CH;

i sCHtO-Noo00,m

CzHsO 15. A compound of the formula cmo s 0 CH; I! ll PsGH,ot -c o 0 CH1 CHzO 16. A mmpound of the rmula 18. A compound of the oinula v flkfi 3 c,mo c 1 Ps-cH2-cLN-c00om CgHsO 5 GIHBO/V V 17; A compound of the fmmula References Cited in the file of this patent Ti V f UNITED STATES PATENTS- PSGHPWMGOOCm' 2,864,849 Sehrader Dec, 16, 1958 c330 10 r V 

12. A COMPOUND OF THE FORMULA 